Effects of Internal Curing by Silica-Containing Polyacrylamide Hydrogel Particles on Autogenous Shrinkage and Mechanical Strength of Mortar

摘要: Composite polyacrylamide hydrogel particles containing silica fume were used to internally cure mortars at a water-to-cement ratio of 0.35. Autogenous shrinkage of mortars was significantly reduced due to the introduction of composite hydrogel particles, with specific compositions contributing to greater reductions in strains. Compressive and flexural strengths of internally cured mortars were comparable to those without hydrogels, despite the expected presence of macrovoids in the cement matrix from hydrogel desorption. This study shows that by altering the crosslinker amount and adding amorphous silica during the synthesis process, the curing performance of polyacrylamide hydrogels can be modified in a way that meets the needs of low-water mixtures without compromising mechanical strength.